Take your Delaware judges idea. If I write a piece on the publishing
propensity of Delaware judges and I explain that propensity on their
status as corporate law experts, does that preempt you from offering a
different explanation? Or would you think that I should be preempted
from even addressing the subject?

Rather than thinking about this as preemption, I think it makes more
sense to think about citations. If you get an idea from a blog post and
you write that idea up in a paper, you should cite to the blog post in
your paper.

We were just talking about this here. I would think of Gordon's article as analogous to a patent claim, and all the other stuff out there as prior art. Some prior art is stronger and more accessible than other. So if Gordon writes his paper, he has a presumption of having advanced the academic art. But if turns out there was a blog on the topic, he is subject to an analog to a validity dispute in the "court" of his academic peers. It continues to be "valid" if it is an advancement on the prior art. It is "invalid" if it is not novel over the pre-existing "claim."

By the way, I think my analogy breaks down on obviousness versus novelty, but the Madisonian.net guys will have to tell me. [Warning: I am about to practice IP law without a license.] You invalidate for lack of novelty if the entire claim is covered by one piece of prior art. You invalidate for obviousness if more than one piece of prior art covered the claim, but it would have been obvious to combine them to one skilled in the art. Most of what we do, I think, is synthesis of ideas, and if it's a new synthesis, almost by definition it's okay.